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Automatic A/c-Heater Systems: Diagnosis Lincoln LS I

Automatic HVAC System 7 illustrations ~14946 words

PRELIMINARY INSPECTION

  1. Verify customer complaints by operating system in all available modes. Carefully check the following for possible cause of problems and repair as necessary: damaged system components, damaged compressor drive belt, compressor clutch, obstructed temperature sensor(s), open fuses, faulty relays, inoperative blower motor, damaged or misrouted wiring circuits, and damaged or disconnected connectors.
  2. If symptom remains after preliminary inspection, connect New Generation Star (NGS) tester (007-00500) to Data Link Connector (DLC). DLC is located beneath instrument panel. Perform DATA LINK DIAGNOSTIC test.
  3. If scan tool displays CKT 914 and CKT 915 = ALL MODULE NO RESP/NOT EQUIP, go to appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT. Test and repair these circuits before proceeding.
  4. If any DATC system related Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) is retrieved, go to «PCM DTC INDEX»(ref-96435-S40444100432001041300000) table. If no DTCs are retrieved, turn A/C off and perform DATC self-diagnostics test. See «SELF-DIAGNOSTICS»(ref-96435-S06534136032001041300000) . If symptom remains, diagnose problem by symptom. See «SYMPTOM INDEX»(ref-96435-S31810387532001041600000) table under SYMPTOM TESTS.
DTC (1)Description
P1460WOT A/C Cutout Internal Driver Malfunction
P1461A/C Pressure Sensor High Input
P1462A/C Pressure Sensor Low Input
P1463Insufficient Pressure Change
P1464A/C Demand Out Of Test Range
(1) See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE for test procedures.
(1)See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE for test procedures.

PCM DTC INDEX

SYMPTOM TESTS

Diagnose a problem by its symptom only if no codes were recorded during self-diagnostics test.

SymptomPerform Test
No Communication With DATC ModuleA
DATC System Inoperative Or Does Not Operate CorrectlyB
Incorrect/Erratic Airflow From OutletsC
Insufficient, Erratic Or No HeatH
Insufficient Heat At Idle (3.9L Engine)I
Full Heat Only In All ModesJ
Dual Temperature Control Inoperative Or Does Not Operate CorrectlyK
A/C System Inoperative Or Does Not Operate CorrectlyL
A/C Is Always OnM
Insufficient A/C CoolingN
Blower Motor Inoperative Or Does Not Operate ProperlyO
Blower Motor Operates Continuously In High SpeedP
Temperature Set Point Does Not Repeat After Turning Ignition Switch OffQ
Exterior Temperature Display Does Not Function CorrectlyR

SYMPTOM INDEX

TEST A: NO COMMUNICATION WITH DATC MODULE

  1. Turn ignition off. Turn headlights on. If DATC backlighting illuminates, go to next step. If DATC backlighting does not illuminate, replace fuse F220 (10-amp) in Central Junction Box (CJB). Recheck system operation.
  2. Turn ignition on. If DATC display and indicators appear when DATC panel buttons are pushed, go to next step. If display and indicators do not appear when DATC panel buttons are pushed, replace fuse F214 (10-amp) in CJB. Recheck system operation.
  3. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Measure resistance between ground and DATC module harness connector C228a terminal No. 2 (Black wire). (Scheme 25) If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in Black wire between DATC module and ground. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  4. Turn ignition on. Measure voltage between ground and DATC module harness connector C228a terminal No. 14 (Orange/Green wire). If more than 10 volts exists, go to next step. If 10 volts or less exists, repair open in Orange/Green wire between DATC module and fuse F220 in CJB. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  5. Measure voltage between ground and DATC module harness connector C228a terminal No. 3 (Pink/Orange wire). If more than 10 volts exists, see appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT. If 10 volts or less exists, repair open in Pink/Orange wire between DATC module and fuse F214 in CJB. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.

Scheme 25

Scheme 25
Scheme 25

TEST B: DATC SYSTEM INOPERATIVE OR DOES NOT OPERATE CORRECTLY

  1. Turn ignition on. Perform self-diagnostic test. See «ENTERING SELF-DIAGNOSTICS»(ref-96435-S03443942982001041300000) under SELF-DIAGNOSTICS. If any DTCs were displayed, see «DATC SELF-DIAGNOSTIC TEST CODE INDEX»(ref-96435-S30839635392001041300000) table under SELF-DIAGNOSTICS. If no DTCs were displayed, go to next step.
  2. Exit self-diagnostic test by pressing any button. See «EXITING SELF-DIAGNOSTICS»(ref-96435-S13323952062001041300000) under SELF-DIAGNOSTICS. Observe symbols displayed. If display is complete, with no missing elements, go to next step. If display is incorrect or incomplete, replace DATC module. Recheck system operation.
  3. Turn ignition on. Press AUTO button. If indicator light above AUTO button illuminates and temperature for driver and passenger appear in DATC display window, go to next step. If indicator light above AUTO button does not illuminate and/or temperature for driver and passenger does not appear in DATC display window, replace DATC module. Recheck system operation.
  4. Start and run engine. Ensure A/C system is operating and blower motor is running. Press OFF button on DATC module. If temperature set point display turns off or reverts to exterior temperature, all indicator lights turn off, and blower motor stops running, go to next step. If temperature set point display does not turn off and/or does not revert to exterior temperature, or all indicator lights do not turn off, and/or blower motor does not stop running, replace DATC module. Recheck system operation.
  5. Press blower speed button to full up (high speed) position and to full down (low speed) position. If blower motor speed goes from high to low and bar graph changes properly in display window, go to next step. If blower motor speed does not change properly or display is incorrect, go to «TEST M: A/C IS ALWAYS ON»(ref-96435-S20175372732001041300000) .
  6. With engine at operating temperature, press panel mode button. Press driver's and passenger's temperature set buttons for warmer and cooler. If each temperature display varies and each temperature varies with selection, go to next step. If each temperature display does not vary and/or each temperature does not vary with selection, go to «TEST H: INSUFFICIENT, ERRATIC OR NO HEAT»(ref-96435-S39633700952001041300000) .
  7. Press panel/floor airflow mode button. If indicator light above panel button illuminates and outside air is discharged from both panel and floor ducts, go to next step. If air is not properly discharged from panel and floor ducts, replace DATC module. Recheck system operation.
  8. Press defrost airflow mode button. If indicator light above defrost button illuminates and outside air is discharged from defroster ducts and side window demisters, go to next step. If indicator light above defrost button does not illuminate, replace DATC module. Recheck system operation. If outside air is not discharged from defrost ducts and side window demisters, go to «TEST C: INCORRECT/ERRATIC AIRFLOW FROM OUTLETS»(ref-96435-S10044524072001041300000) .
  9. Press floor airflow mode button. If indicator light above floor button illuminates and outside air is discharged from floor duct, go to next step. If indicator light above floor button does not illuminate, replace DATC module. Recheck system operation. If outside air is not discharged from floor duct, go to «TEST C: INCORRECT/ERRATIC AIRFLOW FROM OUTLETS»(ref-96435-S10044524072001041300000) .
  10. Press panel airflow mode button. If indicator light above panel button illuminates and outside air is discharged from panel registers, go to next step. If indicator light above panel button does not illuminate, replace DATC module. Recheck system operation. If outside air is not discharged from panel registers, go to «TEST C: INCORRECT/ERRATIC AIRFLOW FROM OUTLETS»(ref-96435-S10044524072001041300000) .
  11. With panel airflow mode selected, press button for recirculation operation. If recirculated air is discharged from panel registers, go to next step. If recirculated is not discharged from panel registers, go to «TEST C: INCORRECT/ERRATIC AIRFLOW FROM OUTLETS»(ref-96435-S10044524072001041300000) .
  12. With panel airflow mode selected, press A/C button. If indicator light illuminates above A/C button and compressor clutch engages, go to next step. If indicator light above panel button does not illuminate and/or compressor clutch does not engage, go to «TEST J: FULL HEAT ONLY IN ALL MODES»(ref-96435-S39911114502001042400000) .
  13. With engine running, press heated wiper park button. If indicator light above heated wiper park button illuminates and wiper rest relay engages, go to next step. If indicator light does not illuminate and/or wiper rest relay does not engage, go to appropriate WIPER/WASHER SYSTEMS article in ACCESSORIES & EQUIPMENT.
  14. With engine running, press REAR defrost button. If indicator illuminates and rear window defrosts, go to next step. If indicator does not illuminate and/or rear window does not defrost, go to appropriate REAR WINDOW DEFOGGERS article in ACCESSORIES & EQUIPMENT.
  15. Repeatedly press °F °C button. If display changes between Fahrenheit and Celsius, go to next step. If display does not change between Fahrenheit and Celsius, replace DATC module. Recheck system operation.
  16. Repeatedly press EXT button. If display changes from temperature set point to external temperature displays, test is complete. System is okay at this time. If display does not change from temperature set points to external temperature displays, go to «TEST O: BLOWER MOTOR INOPERATIVE OR DOES NOT OPERATE PROPERLY»(ref-96435-S02264436132001041300000) .

Scheme 26

Scheme 26: TEST C: INCORRECT/ERRATIC AIRFLOW FROM OUTLETS
Scheme 26: TEST C: INCORRECT/ERRATIC AIRFLOW FROM OUTLETS

Scheme 27

Scheme 27
Scheme 27
  1. Start engine and run at idle. Ensure all registers are open. Adjust blower speed to maximum. In turn, press each override button for A/C, panel, panel/floor, floor, floor/defrost, and FRONT defrost. Check airflow at each setting. If airflow is correct in all mode positions, go to next step. If airflow is not correct for mode selected, go to step 3.
  2. Turn ignition off. Turn ignition on. Request continuous DTCs and perform DATC module self-test. See «ENTERING SELF-DIAGNOSTICS»(ref-96435-S03443942982001041300000) under SELF-DIAGNOSTICS. If no DTCs exist, go to next step. If DTC B1265 exists, go to step 4. If DTC B1242 exists, go to step 18. If DTC B1262 exists, go to step 32. If DTC B1263 exists, go to step 46. If DTC B1264 exists, go to step 60.
  3. Connect New Generation Star (NGS) tester. In ACTIVE COMMAND mode, command actuators to full open and full closed. Record PID values. See «MODE CONTROL DOOR PIDS & VALUES»(ref-96435-S00108019242001041700000) table. If PID BYP-SRV values are out of range, go to step 17. If PID RSRC-SR values are out of range, go to step 31. If PID DEF-SRV values are out of range, go to step 45. If PID PNL-SRV values are out of range, go to step 59. If PID FLR-SRV values are out of range, go to step 73. If PID values are within specification, system is operating properly at this time. Go to «SYMPTOM INDEX»(ref-96435-S31810387532001041600000) table to continue diagnosis. MODE CONTROL DOOR PIDS & VALUES Mode Door PID PID Open PID Closed Recirc RSRC-SR 170-200 30-60 Floor FLR-SRV 170-200 30-60 Panel PNL-SRV 170-200 30-60 Defrost DEF-SRV 170-200 30-60 By-Pass BYP-SRV 170-200 30-60
  4. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Disconnect DATC module 26-pin harness connector C228b. Connect a fused jumper between DATC module harness connector C228a terminal No. 2 (Black wire) and DATC module harness connector C228b terminal No. 11 (White/Red wire). (Scheme 25)and (Scheme 26). Connect a second fused jumper wire between DATC module harness connector C228a terminal No. 14 (Orange/Green wire) and DATC module harness connector C228b terminal No. 12 (Yellow/Red wire). If cold air by-pass door actuator moves to open position, go to next step. If cold air by-pass door actuator does not move to open position, go to step 6.
  5. Connect a fused jumper between DATC module harness connector C228a terminal No. 2 (Black wire) and DATC module harness connector C228b terminal No. 11 (White/Red wire). (Scheme 25)and (Scheme 26). Connect a second fused jumper wire between DATC module harness connector C228a terminal No. 14 (Orange/Green wire) and DATC module harness connector C228b terminal No. 12 (Yellow/Red wire). If cold air by-pass door actuator moves to closed position, go to step 11. If cold air by-pass door actuator does not move to closed position, go to next step.
  6. Disconnect cold air by-pass door actuator 6-pin harness connector C295. Measure resistance between ground and DATC module harness connector C228b terminal No. 11 (White/Red wire). If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in White/Red wire between DATC and cold air by-pass door actuator. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  7. Measure resistance between ground and DATC module harness connector C228b terminal No. 12 (Yellow/Red wire). If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in Yellow/Red wire between DATC and cold air by-pass door actuator. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  8. Measure resistance of White/Red wire between DATC module harness connector C228b terminal No. 11 and cold air by-pass door actuator harness connector C295 terminal No. 1. (Scheme 26)and (Scheme 27). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in White/Red wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  9. Measure resistance of Yellow/Red wire between DATC module harness connector C228b terminal No. 12 and cold air by-pass door actuator harness connector C295 terminal No. 6. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in Yellow/Red wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  10. Remove cold air by-pass door actuator. See «DOOR ACTUATORS»(ref-96435-S28945760552001041300000) under REMOVAL & INSTALLATION. Connect cold air by-pass harness connector to actuator. Disconnect actuator drive from cold air by-pass door. Connect jumper wires as in step 5 and drive cold air by-pass actuator to closed position. Connect jumper cables as in step 4 and drive cold air by-pass actuator to open position. If actuator moves in both directions and it returns to original position, repair stuck or binding cold air by-pass door. Recheck system operation. If actuator does not move in both directions and returns to original position, replace cold air by-pass actuator. Recheck system operation.
  11. Measure resistance between DATC module harness connector C228a terminals No. 11 (Brown wire) and No. 22 (Yellow wire). If resistance is 2-3 k/ohms, go to step 16. If resistance is not 2-3 k/ohms, go to next step.
  12. Disconnect cold air by-pass actuator 6-pin harness connector C295. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and cold air by-pass door actuator harness connector C295 terminal No. 5 (Yellow/Red wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  13. Measure resistance of Brown/Red wire between DATC module harness connector C228a terminal No. 11 and cold air by-pass harness connector C295 terminal No. 4. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in Brown/Red wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  14. Connect fused jumper wires as in step 4. Drive cold air by-pass actuator to full open position. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and DATC module harness connector C228b terminal No. 2 (White/Red wire). If resistance is 250-1500 ohms, go to step 16. If resistance is not 250-1500 ohms, go to next step.
  15. Disconnect cold air by-pass door actuator 6-pin harness connector C295. Measure resistance of White/Red wire between DATC module harness connector C228b terminal No. 2 and cold air by-pass door actuator harness connector C295 terminal No. 3. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in White/Red wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  16. Connect jumper wires as in step 5 and drive cold air by-pass door actuator to full closed position. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and DATC module harness connector C228b terminal No. 2 (White/Red wire). If resistance is 3.5-6 k/ohms, go to step 74. If resistance is not 3.5-6 k/ohms, replace cold air by-pass door actuator. Recheck system operation.
  17. Obtain Parameter Identification (PID) values using step 3. If PID BYP-SRV range is 0-255, check for broken or incorrectly installed actuator. If linkage is okay, replace cold air by-pass actuator. If PID BYP-SRV range is 50-135, check for binding or broken shaft. If shaft is binding or broken, replace housing. If shaft and housing are okay, replace cold air by-pass actuator. Recheck system operation.
  18. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Disconnect DATC module 26-pin harness connector C228b. Connect a fused jumper between DATC module harness connector C228a terminal No. 2 (Black wire) and DATC module harness connector C228b terminal No. 10 (White/Red wire). (Scheme 25)and (Scheme 26). Connect a second fused jumper wire between DATC module harness connector C228a terminal No. 14 (Orange/Green wire) and DATC module harness connector C228b terminal No. 9 (Yellow/Red wire). If air recirculation door actuator moves to open position, go to next step. If air recirculation door actuator does not move to open position, go to step 20.
  19. Connect a fused jumper between DATC module harness connector C228a terminal No. 2 (Black wire) and DATC module harness connector C228b terminal No. 9 (Yellow/Red wire). Connect a second fused jumper wire between DATC module harness connector C228a terminal No. 14 (Orange/Green wire) and DATC module harness connector C228b terminal No. 10 (White/Red wire). If air recirculation door actuator moves to closed position, go to step 25. If air recirculation door actuator does not move to closed position, go to next step.
  20. Disconnect airflow recirculation door actuator 6-pin harness connector C289. Measure resistance between ground and DATC module harness connector C228b terminal No. 10 (White/Red wire). If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in White/Red wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  21. Measure resistance between ground and DATC module harness connector C228b terminal No. 9 (Yellow/Red wire). If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in Yellow/Red wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  22. Measure resistance of White/Red wire between DATC module harness connector C228b terminal No. 10 and airflow recirculation door actuator harness connector C289 terminal No. 6. (Scheme 26)and (Scheme 27). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in White/Red wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  23. Measure resistance of Yellow/Red wire between DATC module harness connector C228b terminal No. 9 and airflow recirculation door actuator harness connector C289 terminal No. 1. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Yellow/Red wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  24. Remove airflow recirculation door actuator. See «DOOR ACTUATORS»(ref-96435-S28945760552001041300000) under REMOVAL & INSTALLATION. Connect airflow recirculation door actuator connector. With actuator drive shaft disengaged from airflow recirculation door, drive actuator to full closed position using step 19. Drive actuator to full open position using 18. If airflow recirculation door actuator moves to both open and closed positions, repair airflow recirculation door. Recheck system operation. If airflow recirculation door actuator does not move to both open and closed positions, replace airflow recirculation door actuator. Recheck system operation.
  25. Connect jumper wires as in step 18. Drive airflow recirculation door actuator door to full open position. Measure resistance between DATC module harness connector C228a terminals No. 11 (Brown wire) and No. 22 (Yellow wire). If resistance is 2-3 k/ohms, go to step 30. If resistance is not 2-3 k/ohms, go to next step.
  26. Disconnect airflow recirculation door actuator 6-pin harness connector C289. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and airflow recirculation door actuator harness connector C289 terminal No. 4 (Yellow/Red wire). (Scheme 26)and (Scheme 27). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in Yellow wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  27. Measure resistance between DATC module harness connector C228a terminal No. 11 (Brown wire) and airflow recirculation door actuator harness connector C289 terminal No. 5 (Brown/Red wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  28. Connect jumper wires as in step 19. Drive airflow recirculation door actuator to closed position. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and DATC module harness connector C228b terminal No. 15 (White/Red wire). If resistance is 250-1500 ohms, go to step 30.
  29. Disconnect airflow recirculation door actuator 6-pin harness connector C289. Measure resistance of White/Red wire between DATC module harness connector C228b terminal No. 15 and airflow recirculation door actuator harness connector C289 terminal No. 3. (Scheme 26)and (Scheme 27). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in White/Red wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  30. Connect jumper wires as in step 18. Drive actuator to full open position. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and DATC module harness connector C228b terminal No. 15 (White/Red wire). If resistance is 250-1500 ohms, go to step 74. If resistance is not 250-1500 ohms, replace airflow recirculation door actuator. Recheck system operation.
  31. Obtain Parameter Identification (PID) values using step 3. If PID RSRC-SR range is 0-255, check for broken or incorrectly installed actuator. If linkage is okay, replace airflow recirculation door actuator. If PID RSRC-SR range is 50-135, check for binding or broken shaft. If shaft is binding or broken, replace housing. If shaft and housing are okay, replace airflow recirculation door actuator. Recheck system operation.
  32. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Disconnect DATC module 26-pin harness connector C228b. Connect a fused jumper between DATC module harness connector C228a terminal No. 2 (Black wire) and DATC module harness connector C228b terminal No. 13 (White/Black wire). (Scheme 25)and (Scheme 26). Connect a second fused jumper wire between DATC module harness connector C228a terminal No. 14 (Orange/Green wire) and DATC module harness connector C228b terminal No. 26 (Yellow/Black wire). If defrost door actuator moves to closed position, go to next step. If defrost door actuator does not move to closed position, replace DATC module. Recheck system operation. If system operates properly, test is complete. If system still does not operate properly, reinstall original DATC and go to step 34.
  33. Connect a fused jumper between DATC module harness connector C228a terminal No. 2 (Black wire) and DATC module harness connector C228b terminal No. 26 (Yellow/Black wire). Connect a second fused jumper wire between DATC module harness connector C228a terminal No. 14 (Orange/Green wire) and DATC module harness connector C228b terminal No. 13 (White/Black wire). If defrost door actuator moves to open position, go to step 39. If defrost door actuator does not move to open position, replace DATC module. Recheck system operation. If system operates properly, test is complete. If system still does not operate properly, reinstall original DATC and go to next step.
  34. Disconnect defrost door actuator 6-pin harness connector C232. Measure resistance between ground and DATC module harness connector C228b terminal No. 13 (White/Black wire). If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in White/Black wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  35. Measure resistance between ground and DATC module harness connector C228b terminal No. 26 (Yellow/Black wire). If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in Yellow/Black wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  36. Measure resistance of White/Black wire between DATC module harness connector C228b terminal No. 13 and defrost door actuator harness connector C232 terminal No. 6. (Scheme 26)and (Scheme 27). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in White/Black wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  37. Measure resistance of Yellow/Black wire between DATC module harness connector C228b terminal No. 26 and defrost door actuator harness connector C232 terminal No. 1. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Yellow/Black wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  38. Remove defrost door actuator. See «DOOR ACTUATORS»(ref-96435-S28945760552001041300000) under REMOVAL & INSTALLATION. Connect defrost door actuator connector. With actuator drive shaft disengaged from defrost door, drive actuator to full open position using step 33. Drive actuator to full closed position using step 32. If defrost door actuator moves to both open and closed positions, repair defrost door. Recheck system operation. If defrost door actuator does not move to both open and closed positions, replace defrost door actuator. Recheck system operation.
  39. Connect jumper wires as in step 32. Drive defrost door actuator door to full closed position. Measure resistance between DATC module harness connector C228a terminals No. 22 (Yellow wire) and DATC module harness connector C228b terminal No. 17 (Brown/Red wire). If resistance is 1.7-2.3 k/ohms, go to step 44. If resistance is not 1.7-2.3 k/ohms, replace DATC module. Recheck system operation. If system operates properly, test is complete. If system still does not operate properly, reinstall original DATC and go to next step.
  40. Disconnect defrost door actuator 6-pin harness connector C232. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and defrost door actuator harness connector C232 terminal No. 4 (Yellow/Black wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  41. Measure resistance between DATC module harness connector C228b terminal No. 17 (Brown/Red wire) and defrost door actuator C232 terminal No. 5 (Brown/Yellow wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  42. Connect jumper wires as in step 32. Drive defrost door actuator to closed position. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and DATC module harness connector C228b terminal No. 1 (White/Black wire). If resistance is 3.5-6 k/ohms, go to step 44. If resistance is not 3.5-6 k/ohms, go to next step.
  43. Disconnect defrost door actuator 6-pin harness connector C232. Measure resistance of White/Black wire between DATC module harness connector C228b terminal No. 1 and defrost door actuator harness connector C232 terminal No. 3. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in White/Black wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  44. Connect jumper wires as in step 33 and drive defrost door actuator to full open position. Measure resistance between DATC module C228a terminal 22 (Yellow wire) and DATC module harness connector C228b terminal No. 1 (White/Black wire). If resistance is 250-1500 ohms, go to step 74. If resistance in not 250-1500 ohms, replace defrost door actuator. Recheck system operation.
  45. Obtain PID values using step 3. If PID DEF-SRV range varied between 0-255, check for broken linkage or incorrectly installed actuator. If linkage and installation are okay, replace defrost door actuator. Recheck system operation. If PID range varied between 50-135, check for binding or broken shaft. If shaft is binding or broken, replace housing. If shaft and housing are okay, replace defrost door actuator. Recheck system operation.
  46. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Disconnect DATC module 26-pin harness connector C228b. Connect a fused jumper between DATC module harness connector C228a terminal No. 2 (Black wire) and DATC module harness connector C228b terminal No. 24 (White wire). (Scheme 25)and (Scheme 26). Connect a second fused jumper wire between DATC module harness connector C228a terminal No. 14 (Orange/Green wire) and DATC module harness connector C228b terminal No. 25 (Yellow wire). If panel door actuator moves to closed position, go to next step. If panel door actuator does not move to closed position, replace DATC module. Recheck system operation. If system operates properly, test is complete. If system still does not operate properly, reinstall original DATC and go to step 48.
  47. Connect fused jumper wire between DATC module harness connector C228a terminal No. 2 (Black wire) and DATC module harness connector C228b terminal No. 25 (Yellow wire). Connect a second fused jumper wire between DATC module harness connector C228a terminal No. 14 (Orange/Green wire) and DATC module harness connector C228b terminal No. 24 (White wire). If panel door actuator moves to open position, go to step 53. If panel door actuator does not move to open position, replace DATC module. Recheck system operation. If system operates properly, test is complete. If system still does not operate properly, reinstall original DATC module and go to next step.
  48. Disconnect panel door actuator 6-pin harness connector C236. Measure resistance between ground and DATC module harness connector C228b terminal No. 24 (White wire). If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in White wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  49. Measure resistance between ground and DATC module harness connector C228b terminal No. 25 (Yellow wire). If resistance is more than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair short to ground in Yellow wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  50. Measure resistance of White wire between DATC module harness connector C228b terminal No. 24 and panel door actuator harness connector C236 terminal No. 6. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in White wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  51. Measure resistance of Yellow wire between DATC module harness connector C228b terminal No. 24 and panel door actuator harness connector C236 terminal No. 1. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in Yellow wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  52. Remove panel door actuator. See «DOOR ACTUATORS»(ref-96435-S28945760552001041300000) under REMOVAL & INSTALLATION. Connect panel door actuator connector. With actuator drive shaft disengaged from panel door, drive actuator to full open position using step 47. Drive actuator to full closed position using step 46. If panel door actuator moves to both open and closed positions, repair panel door. Recheck system operation. If panel door actuator does not move to both open and closed positions, replace panel door actuator. Recheck system operation.
  53. Drive panel door actuator to open position using step 47. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and DATC module harness connector C228b terminal No. 17 (Brown/Red wire). If resistance is 1.7-2.3 k/ohms, go to step 58. If resistance is not 1.7-2.3 k/ohms, replace DATC module. Recheck system operation. If system operates properly, test is complete. If system still does not operate properly, reinstall original DATC module and go to next step.
  54. Disconnect panel door actuator 6-pin harness connector C236. Measure resistance of Yellow wire between DATC module harness connector C228a terminal No. 22 and panel door actuator C236 terminal No. 5. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance is Yellow wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  55. Measure resistance between DATC module harness connector C228b terminal No. 17 (Brown/Red wire) and panel door actuator C236 terminal No. 5 (Brown wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  56. Drive panel door actuator to closed position using step 46. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and DATC module harness connector C228b terminal No. 3 (White wire). If resistance is 250-1500 ohms, go to step 58. If resistance is not 250-1500 ohms, replace DATC module. Recheck system operation. If system operates properly, test is complete. If system still does not operate properly, reinstall original DATC module and go to next step.
  57. Disconnect panel door actuator 6-pin harness connector C236. Measure resistance of White wire between DATC module harness connector C228b terminal No. 3 and panel door actuator harness connector C236 terminal No. 3. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in White wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  58. Drive panel door to open position using step 47. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and DATC module harness connector C228b terminal No. 3 (White wire). If resistance is 250-1500 ohms go to step 74. If resistance is not 250-1500 ohms, replace panel door actuator. Recheck system operation.
  59. Obtain PID values using step 3. If PID PNL-SRV range varied between 0-255, check for broken linkage or incorrectly installed actuator. If linkage and installation are okay, replace defrost door actuator. Recheck system operation. If PID range varied between 50-135, check for binding or broken shaft. If shaft is binding or broken, replace housing. If shaft and housing are okay, replace defrost door actuator. Recheck system operation.
  60. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Disconnect DATC module 26-pin harness connector C228b. Connect a fused jumper between DATC module harness connector C228a terminal No. 2 (Black wire) and DATC module harness connector C228b terminal No. 22 (White/Violet wire). (Scheme 25)and (Scheme 26). Connect a second fused jumper wire between DATC module harness connector C228a terminal No. 14 (Orange/Green wire) and DATC module harness connector C228b terminal No. 23 (Yellow/Violet wire). If floor door actuator moves to closed position, go to next step. If floor door actuator does not move to closed position, go to step 62.
  61. Connect a fused jumper between DATC module harness connector C228a terminal No. 2 (Black wire) and DATC module harness connector C228b terminal No. 23 (Yellow/Violet wire). (Scheme 25)and (Scheme 26). Connect a second fused jumper wire between DATC module harness connector C228a terminal No. 14 (Orange/Green wire) and DATC module harness connector C228b terminal No. 22 (White/Violet wire). If floor door actuator moves to open position, go to step 67. If floor door actuator does not move to open position, go to next step.
  62. Disconnect floor door actuator 6-pin harness connector C234. Measure resistance between ground and DATC module harness connector C228b terminal No. 22 (White/Violet wire). If resistance is greater than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in White/Violet wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  63. Measure resistance between ground and DATC module harness connector C228b terminal No. 23 (Yellow/Violet wire). If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in Yellow/Violet wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  64. Measure resistance of White/Violet wire between DATC module harness connector C228b terminal No. 22 and floor door actuator harness connector C234 terminal No. 1. (Scheme 26)and (Scheme 27). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in White/Violet wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  65. Measure resistance of Yellow/Violet wire between DATC module harness connector C228b terminal No. 23 and floor door actuator harness connector C234 terminal No. 6. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in Yellow/Violet wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  66. Remove floor door actuator. See «DOOR ACTUATORS»(ref-96435-S28945760552001041300000) under REMOVAL & INSTALLATION. Connect floor door actuator connector. With actuator drive shaft disengaged from panel door, drive actuator to full open position using step 61. Drive actuator to full closed position using step 60. If floor door actuator moves to both open and closed positions, repair floor door. Recheck system operation. If floor door actuator does not move to both open and closed positions, replace floor door actuator. Recheck system operation.
  67. Drive floor door actuator to full open position using step 61. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and DATC module harness connector C228b terminal No. 17 (Brown/Red wire). If resistance is 1.7-2.3 k/ohms, go to step 72. If resistance is not 1.7-2.3 k/ohms, go to next step.
  68. Disconnect floor door actuator 6-pin harness connector C234. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and floor door actuator harness connector C234 terminal No. 2 (Yellow/Violet wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  69. Measure resistance between DATC module harness connector C228b terminal No. 17 (Brown/Red wire) and floor door actuator harness connector C234 terminal No. 3 (Brown/White wire). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  70. Drive floor door actuator to full closed position using step 60. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and DATC module harness connector C228b terminal No. 16 (White/Violet wire). If resistance is 3.5-6 k/ohms, go to step 72. If resistance is not 3.5-6 k/ohms, go to next step.
  71. Disconnect floor door actuator 6-pin harness connector C234. Measure resistance of White/Violet wire between DATC module harness connector C228 terminal No. 16 and floor door actuator harness connector C234 terminal No. 2. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in White/Violet wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  72. Drive floor door actuator to full open position using step 61. Measure resistance between DATC module harness connector C228a terminal No. 22 (Yellow wire) and DATC harness connector C228b terminal No. 16 (White/Violet wire). If resistance is 250-1500 ohms, go to step 74. If resistance is not 250-1500 ohms, replace floor door actuator. Recheck system operation.
  73. Obtain Parameter Identification (PID) values using step 3. If PID FLR-SRV range varied between 0-255, check for broken linkage or incorrectly installed actuator. If linkage and installation are okay, replace defrost door actuator. Recheck system operation. If PID range varied between 50-135, check for binding or broken shaft. If shaft is binding or broken, replace housing. If shaft and housing are okay, replace floor door actuator. Recheck system operation.
  74. Measure resistance between ground and DATC module harness connector C228a terminal No. 22 (Yellow wire). If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in Yellow wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  75. Measure resistance between ground and DATC module harness connector C228b terminal No. 17 (Brown/Red wire). If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohm or less, repair short to ground in Brown/Red wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  76. Measure resistance between ground and DATC module harness connector C228b terminal No. 16 (White/Violet wire). If resistance is more than 10 k/ohms, replace floor door actuator. Recheck system operation. If resistance is 10 k/ohms or less, repair short to ground in White/Violet wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.

TEST D: IN-CAR TEMPERATURE SENSOR NOT OPERATING CORRECTLY

  1. Turn ignition off. Disconnect in-car temperature sensor 2-pin harness connector C233, located under top center of instrument panel. Measure resistance between in-car temperature sensor terminals. See «TEMPERATURE SENSOR RESISTANCE»(ref-96435-S24266204942001041300000) table. If resistance is within specification, go to next step. If resistance is not within specification, replace in-car temperature sensor. Recheck system operation. TEMPERATURE SENSOR RESISTANCE Temperature - °F (°C) K/Ohms 50-68 (10-20) 37-58 68-86 (20-30) 24-37 86-104 (30-40) 16-24
  2. Turn ignition on. Press AUTO button on DATC panel. Measure voltage between in-car temperature sensor harness connector C233 White/Orange wire and Pink/Black wire terminals. If 4.7-5.1 volts exists, go to step 6. If 4.7-5.1 volts does not exist and DTC B1253 exists, go to next step. If 4.7-5.1 volts does not exist and DTC B1251 exists, go to step 4.
  3. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Measure resistance between ground and DATC module connector C228a terminal No. 9 (White/Green wire). (Scheme 25) If resistance is more than 10 k/ohms, go to step 6. If resistance is 10 k/ohms or less, repair short to ground in White/Green wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  4. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Measure resistance of White/Green wire between DATC module harness connector C228a terminal No. 9 and in-car temperature sensor harness connector C233. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in White/Green wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  5. Disconnect DATC module 26-pin harness connector C228b. Measure resistance of Brown/Green wire between DATC module harness connector C228b terminal No. 14 and in-car temperature sensor harness connector C233. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in Brown/Green wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  6. Disconnect DATC module 26-pin harness connector C228b. Inspect in-car temperature sensor connector pins, and DATC harness connector C228b terminal No. 14 (Brown/Green wire) and DATC module harness connector C228a terminal No. 9 (White/Green wire) for damage, loose fit or improper installation. If all wiring is undamaged and properly connected, replace DATC module. Recheck system operation. If wiring shows signs of damage or incorrect connections, repair wiring as needed. Recheck system operation.

TEST E: EVAPORATOR OR HEATER CORE DISCHARGE AIR TEMPERATURE SENSORS NOT OPERATING CORRECTLY

Note. Evaporator core, driver's side heater core and passenger's side heater core discharge air temperature sensors use the same diagnostic procedure.

  1. Turn ignition off. Disconnect sensor associated with DTC retrieved from DATC module self-test. See «AIR TEMPERATURE SENSOR IDENTIFICATION»(ref-96435-S06919121472001041900000) table. Measure resistance between sensor terminals. See «TEMPERATURE SENSOR RESISTANCE»(ref-96435-S24266204942001041300000) table. If resistance is within specification, go to next step. If resistance is not within specification, replace appropriate sensor. Recheck system operation. AIR TEMPERATURE SENSOR IDENTIFICATION DTC Sensor Condition Connector B1946 Evap. Air Discharge Open C296 B1947 Evap. Air Discharge Short C296 B1966 Driver Air Open C255 B1967 Driver Air Short C255 B2428 Passenger Air Open C235 B2429 Passenger Air Short C235
  2. Turn ignition on. Measure voltage between temperature sensor harness connector terminals. If 4.7-5.1 volts exists, go to step 6 . If 4.7-5.1 volts does not exist and DTC B1946, B1966 or B2428 exists, go to next step. If 4.7-5.1 volts does not exist and DTC B1947, B1967 or B2429 exists, go to step 4 . TEMPERATURE SENSOR CONNECTOR TERMINAL IDENTIFICATION Connector Terminal Wire Color Terminal Wire Color C296 White/Red Brown/Red C255 White/Black Brown/Yellow C235 White/Green Brown/Green
  3. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Measure resistance between DATC module harness connector C228a terminals and air temperature sensor harness connector terminal as specified. See «AIR TEMPERATURE SENSOR CIRCUIT RESISTANCE»(ref-96435-S33882556682001041900000) table. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation. AIR TEMPERATURE SENSOR CIRCUIT RESISTANCE DATC Connector Terminal No. Sensor (Connector) Wire Color 6 Passenger (C255) White/Black 10 Evap. Discharge (C296) White/Red 18 Driver (C235) White/Green
  4. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Measure resistance between ground and DATC module harness connector and suspect air temperature sensor harness connector. See «AIR TEMPERATURE SENSOR REFERENCE CIRCUIT IDENTIFICATION»(ref-96435-S18927692832001041900000) table. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation. AIR TEMPERATURE SENSOR REFERENCE CIRCUIT IDENTIFICATION DATC Connector Terminal No. Wire Color Air Temperature Sensor 6 White/Black Passenger 10 White/Red Evaporator 18 White/Green Driver
  5. Measure resistance between DATC module harness connector C228a and suspect air temperature sensor. See «AIR TEMPERATURE SENSOR RETURN CIRCUIT IDENTIFICATION»(ref-96435-S28051943312001041900000) table. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation. AIR TEMPERATURE SENSOR RETURN CIRCUIT IDENTIFICATION DATC Connector Terminal No. Wire Color Air Temperature Sensor 16 Brown/Red Evaporator 19 Brown/Blue Passenger 19 Brown/Blue Driver
  6. Inspect suspect air temperature sensor connector pins, and DATC module harness connector C228a terminals for damage, loose fit or improper installation. If all wiring is undamaged and properly connected, reconnect all connectors and perform DATC self-diagnostic test. If DTC(s) still exist, replace DATC module. Recheck system operation. If wiring shows signs of damage or incorrect connections, repair wiring and/or connectors as needed. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation.

TEST H: INSUFFICIENT, ERRATIC OR NO HEAT

  1. Check coolant level with engine cold and with engine hot. If coolant is at proper level, go to next step. If coolant is not at proper level, go to step 4.
  2. Fill and bleed engine cooling system. Pressure test cooling system and radiator cap. If cooling system holds pressure, go to next step. If cooling system does not hold pressure, repair cooling system as necessary.
  3. Start engine and warm to normal operating temperature. Set DATC module driver and passenger temperature to maximum hot. Allow time for system to respond and check discharge air temperature. Discharge temperature at full hot should be about 90°F (32°C). If discharge air temperature is as specified, test is complete. If discharge air temperature is not as specified, go to next step.
  4. Bleed cooling system. Start engine and warm to normal operating temperature. Set driver and passenger temperature to maximum hot. Allow time for system to respond and check discharge air temperature. Discharge temperature at full hot should be about 90°F (32°C). If discharge air temperature is as specified, test is complete. If discharge air temperature is not as specified, go to next step.
  5. Start engine and warm to normal operating temperature. Feel both heater core inlet hoses at inlet connection. If both hoses are hot to touch, pressure test heater core. See «HEATER CORE»(ref-96435-S26667252302001041300000) under COMPONENT TESTS. If hose is not hot, go to next step.
  6. Disconnect coolant control valve jumper 3-pin harness connector C1034. Disconnect engine compartment 6-pin wiring harness connector C134. Start engine and warm to normal operating temperature. On 3.9L engines, run engine at 3000 RPM to compensate for disconnected auxiliary coolant pump. On all vehicles, with engine at normal operating temperature, set driver and passenger temperature to maximum hot. Allow time for system to respond and check discharge air temperature. Discharge temperature at full hot should be about 90°F (32°C). If discharge air temperature is as specified, go to step 8. If discharge air temperature is not as specified, go to next step.
  7. Turn ignition off. Check thermostat. Thermostat should open at 192-199°F (88.9-92.8°C) and be fully open at 219°F (104°C). If thermostat is operating correctly, replace coolant control valve. Recheck system operation. If thermostat is not operating correctly, replace thermostat. Recheck system operation.
  8. Measure voltage between ground and Underhood Auxiliary Junction Box (UAJB) fuse F101 Red wire terminal. If more than 10 volts exists, go to next step. If 10 volts or less exists, repair open in Red or Red/Orange wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  9. Measure voltage between UAJB fuse F101 Red wire terminal and engine compartment wiring harness connector C134 terminal No. 6 (Brown/Green wire). (Scheme 28) If more than 10 volts exists, go to step 11. If 10 volts or less exists, go to next step.
  10. Measure voltage between UAJB fuse F101 Red wire terminal and engine compartment wiring harness connector C134 terminal No. 3 (Brown/Blue wire). If more than 10 volts exists, go to step 12. If 10 volts or less exists, go to step 13.
  11. Turn ignition off. Disconnect DATC module 26-pin harness connector C228b. Measure resistance between ground and engine compartment wiring harness connector C134 terminal No. 6 (Brown/Green wire). If resistance is more than 10 k/ohms, replace DATC module. Recheck system operation. If resistance is 10 k/ohms or less, repair short to ground in Brown/Green wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  12. Turn ignition off. Disconnect DATC module 26-pin harness connector C228b. Measure resistance between ground and engine compartment wiring harness connector C134 terminal No. 4 (Brown/Blue wire). If resistance is more than 10 k/ohms, replace DATC module. Recheck system operation. If resistance is 10 k/ohms or less, repair short to ground in Brown/Blue wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  13. Turn ignition off. Measure resistance between coolant control valve jumper harness connector C134 terminals No. 4 (Red/Orange wire) and No. 6 (Brown/Green wire). Measure resistance between coolant control valve jumper harness connector C134 terminals No. 4 (Red/Orange wire) and No. 3 (Brown/Blue wire). If both resistances are 10-23 ohms, replace coolant control valve. Recheck system operation. If resistance is more than 23 ohms, go to next step. If resistance is less than 10 ohms, go to step 15.
  14. Measure resistance of Red/Orange wire between coolant control valve jumper harness connector C134 terminal No. 4 and coolant control valve harness connector C1034 terminal No. 2. Measure resistance of Brown/Blue wire between coolant control valve jumper harness connector C134 terminal No. 3 and coolant control valve harness connector C1034 terminal No. 3. Measure resistance of Brown/Green wire between coolant control valve jumper harness connector C134 terminal No. 6 and coolant control valve harness connector C1034 terminal No. 1. If resistances are less than 5 ohms in all cases, replace coolant control valve. Recheck system operation. If system operation is still not correct, replace DATC module. Recheck system operation. If any resistance is 5 ohms or more, repair open or high resistance in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  15. Measure resistance between coolant control valve jumper harness connector C134 terminals No. 3 (Brown/Blue wire) and No. 4 (Red/Orange wire). Measure resistance between coolant control valve jumper harness connector C134 terminals No. 6 (Brown/Green wire) and No. 4 (Red/Orange wire). If resistances are more than 10 k/ohms, replace coolant control valve. Recheck system operation. If both/either resistance is 10 k/ohms or less, repair appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation. If system operation is still not correct, replace DATC module. Recheck system operation.

Scheme 28

Scheme 28: 3.9L Engine
Scheme 28: 3.9L Engine
  1. Turn ignition on. Perform DATC module self-diagnostic test and retrieve and record continuous DTCs. See «ENTERING SELF-DIAGNOSTICS»(ref-96435-S03443942982001041300000) under SELF-DIAGNOSTICS. If any DTCs exist, see «DATC SELF-DIAGNOSTIC TEST CODE INDEX»(ref-96435-S30839635392001041300000) under SELF-DIAGNOSTICS. Perform appropriate test as directed. If no DTCs exist, go to next step.
  2. Connect New Generation Star (NGS) tester. Enter MODEL IDENTIFICATION mode. Read PID CNFG data 1. If data reads 4N3N2Y, go to next step. If data does not read 4N3N2Y, reconfigure DATC module using NGS tester.
  3. Check coolant level with engine hot and cold. If coolant level is okay, go to next step. If coolant level is not okay, fill system and pressure check engine cooling system for leaks. Repair as necessary.
  4. Turn ignition on. Using NGS tester in ACTIVE COMMAND mode, request climate control system. Select PUMP/VCB or set driver's side to 90°F (32°C). If auxiliary cooling pump can be heard or felt running, system is operating properly at this time. If auxiliary cooling pump cannot be heard or felt running, go to next step.
  5. Turn ignition off. Disconnect auxiliary coolant pump 2-pin harness connector C163. Turn ignition on. Ensure active command PUMP/VCB is still selected and/or driver's side temperature is set to 90°F (32°C). Measure voltage between auxiliary coolant pump harness connector C163 Red/Yellow wire and Black wire terminals. If more than 10 volts exists, check auxiliary coolant pump and connector terminals for proper terminal contact. If terminal contact is okay, replace auxiliary coolant pump. Recheck system operation.
  6. Measure resistance between ground and auxiliary coolant pump harness connector C163 Black wire terminal. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in Black wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  7. Turn ignition off. Remove auxiliary coolant pump relay from auxiliary junction box, located in right front of engine compartment. Measure voltage between ground and auxiliary coolant pump relay socket terminals No. 2 (Brown/Blue wire) and No. 5 (Red/Yellow wire). (Scheme 29) If more than 10 volts exists, go to next step. If 10 volts or less exists, repair open in Red/Yellow wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  8. Test auxiliary coolant pump relay. See «MICRO ISO RELAY»(ref-96435-S09731459222001042400000) under COMPONENT TESTS. If relay is okay, go to next step. If relay is not okay, replace auxiliary coolant pump relay. Recheck system operation.
  9. Remove auxiliary coolant pump relay from auxiliary junction box, located in right front of engine compartment. Measure resistance of Red/Yellow wire between auxiliary coolant pump harness connector C163 terminal and auxiliary coolant pump relay socket terminal No. 5. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open or high resistance in Red/Yellow wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  10. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Disconnect DATC module 26-pin harness connector C228b. Connect a fused jumper wire between DATC module harness connector C228a terminal No. 2 (Black wire) and DATC module harness connector C228b terminal No. 18 (Brown/Blue wire). If auxiliary coolant pump motor operates, check all connectors and terminals. Reconnect all connectors. Recheck system operation. If auxiliary coolant pump motor does not operate, go to next step.
  11. Measure voltage between ground and auxiliary coolant pump relay socket terminal No. 2 (Brown/Blue wire). If any voltage exists, repair short to power in Brown/Blue wire. Short to power also damages DATC, replace DATC module. Recheck system operation. If no voltage exists, go to next step.
  12. Measure resistance of Brown/Blue wire between auxiliary coolant pump relay socket terminal No. 2 and DATC module harness connector C228b terminal No. 18. If resistance is less than 5 ohms, check all connectors for proper terminal contact. Repair as necessary. Connect all connectors. Recheck system operation. If problem still exists, replace DATC module. Recheck system operation. If resistance is 5 ohms or more, repair open or high resistance in Brown/Blue wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.

TEST J: FULL HEAT ONLY IN ALL MODES

CAUTIONTo avoid damage to DATC module, DO NOT short engine compartment harness connector C134 (male side) terminals No. 3 or 6 to terminals No. 1 or 4. Coolant control valve jumper harness-to-engine compartment wiring harness connector halves are identified as engine compartment wiring harness connector C134 (male side and female side). (Scheme 28) Carefully identify the correct half of connector C134 before carrying out any electrical measurements.

Scheme 29

Scheme 29
Scheme 29
  1. Turn ignition off. Disconnect 6-pin engine compartment harness connector C134. Measure voltage between ground and male side of engine compartment wiring harness connector C134 terminal No. 4 (Red/Orange wire). If more than 10 volts exists, go to next step. If 10 volts or less exists, repair open in Red/Orange wire or Red wire between engine compartment wiring harness connector C134 and underhood auxiliary junction box. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  2. Measure resistance between female side of engine compartment wiring harness connector C134 terminals No. 4 (Red/Orange wire) and No. 6 (Brown/Green wire). If resistance is 10-23 ohms, go to next step. If resistance is more than 23 ohms, go to step 7. If resistance is less than 10 ohms, go to step 9.
  3. Measure resistance between female side of engine compartment wiring harness connector C134 terminals No. 4 (Red/Orange wire) and No. 3 (Brown/Blue wire). If resistance is 10-23 ohms, go to next step. If resistance is more than 23 ohms, go to step 8. If resistance is less than 10 ohms, go to step 10.
  4. Measure voltage between ground and underhood auxiliary junction box fuse F101 (10-amp) Red wire terminal. If more than 10 volts exists, go to next step. If 10 volts or less exists, repair open in Red wire or Red/Orange wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Go to next step.
  5. Turn ignition on. Press panel button and set driver and passenger temperature controls to full cool. Measure voltage between UAJB fuse F101 Red wire terminal and female side of engine compartment wiring harness connector C134 terminal No. 6 (Brown/Green wire). If more than 10 volts exists, go to next step. If 10 volts or less exists, go to step 11.
  6. Measure voltage between UAJB fuse F101 Red wire terminal and male side of engine compartment wiring harness connector C134 terminal No. 3 (Brown/Blue wire). If more than 10 volts exists, replace coolant control valve. Recheck system operation. If 10 volts or less exists, go to step 12.
  7. Disconnect coolant control valve 3-pin harness connector C1034. Measure resistance of Red/Orange wire between female side of engine compartment wiring harness connector C134 terminal No. 4 and coolant control valve harness connector C1034 terminal No. 2. (Scheme 28)and (Scheme 30). Measure resistance of Brown/Green wire between female side of engine compartment wiring harness connector C134 terminal No. 6 and coolant control valve harness connector C1034 terminal No. 1. If resistances are less than 5 ohms, replace coolant control valve. Recheck system operation. If resistance is 5 ohms or more, repair open or high resistance in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  8. Disconnect coolant control valve 3-pin harness connector C1034. Measure resistance of Red/Orange wire between female side of engine compartment wiring harness connector C134 terminal No. 4 and coolant control valve harness connector C1034 terminal No. 2. Measure resistance of Brown/Blue wire between female side of engine compartment wiring harness connector C134 terminal No. 3 and coolant control valve harness connector C1034 terminal No. 3. If resistances are less than 5 ohms, replace coolant control valve. Recheck system operation. If resistance is 5 ohms or more, repair open or high resistance in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  9. Disconnect coolant control valve 3-pin harness connector C1034. Measure resistance between female side of engine compartment wiring harness connector C134 terminals No. 4 (Red/Orange wire) and No. 6 (Brown/Green wire). If resistance is greater than 10 k/ohms, replace coolant control valve. Recheck system operation. If resistance is 10 k/ohms or less, repair short in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  10. Disconnect coolant control valve 3-pin harness connector C1034. Measure resistance between female side of engine compartment wiring harness connector C134 terminals No. 4 (Red/Orange wire) and No. 3 (Brown/Blue wire). If resistance is greater than 10 k/ohms, replace coolant control valve. Recheck system operation. If resistance is 10 k/ohms or less, repair short in appropriate wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  11. Turn ignition off. Disconnect DATC module 26-pin harness connector C228b. Measure resistance of Brown/Green wire between male side of engine compartment wiring harness connector C134 terminal No. 6 and DATC module harness connector C228b terminal No. 6. If resistance is less than 5 ohms, go to step 13. If resistance is 5 ohms or more, repair open or high resistance in Brown/Green wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  12. Turn ignition off. Disconnect 26-pin harness connector C228b. Measure resistance of Brown/Blue wire between male side of engine compartment wiring harness connector C134 terminal No. 3 and DATC module harness connector C228b terminal No. 5. If resistance is less than 5 ohms, go to step 14. If resistance is 5 ohms or more, repair open or high resistance in Brown/Green wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  13. Turn ignition on. Measure voltage between ground and male side of engine compartment wiring harness connector C134 terminal No. 6 (Brown/Green wire). If voltage does not exist, go to step 15. If any voltage exists, repair short to power in Brown/Green wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  14. Turn ignition on. Measure voltage between ground and male side of engine compartment wiring harness connector C134 terminal No. 3 (Brown/Green wire). If voltage does not exist, go to step 16. If any voltage exists, repair short to ground in Brown/Green wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  15. Turn ignition off. Disconnect coolant control valve 3-pin harness connector C1034. Measure resistance between female side of engine compartment wiring harness connector C134 terminals No. 4 (Red/Orange wire) and No. 6 (Brown/Green wire). On vehicles with 3.9L engine, measure resistance between female side of engine compartment wiring harness connector C134 terminals No. 1 (Red/Yellow wire) and No. 6 (Brown/Green wire). On all models, if resistance is more than 10 k/ohms, replace DATC module. Recheck system operation. If resistance is 10 k/ohms or less, repair short in appropriate wire(s). Recheck system operation. If problem still exists, replace DATC module.
  16. Turn ignition off. Disconnect coolant control valve 3-pin harness connector C1034. Measure resistance between female side of engine compartment wiring harness connector C134 terminals No. 3 (Brown/Blue wire) and No. 4 (Red/Orange wire). On vehicles with 3.9L engine, measure resistance between female side of harness connector C134 terminals No. 1 (Red/Yellow wire) and No. 3 (Brown/Blue wire). On all models, if resistance is more than 10 k/ohms, replace DATC module. Recheck system operation. If resistance is 10 k/ohms or less, repair short in appropriate wire(s). Recheck system operation. If problem still exists, replace DATC module.

TEST K: DUAL TEMPERATURE CONTROL INOPERATIVE OR DOES NOT OPERATE PROPERLY

CAUTIONCoolant control valve jumper harness-to-engine compartment wiring harness connector halves are identified as C134. To avoid damage to DATC module, carefully identify the correct half of connector C134 before carrying out any electrical measurements. (Scheme 28)
  1. Check coolant level with engine at hot and cold temperature. If coolant level is okay, go to next step. If coolant level is not okay, refill and pressure test cooling system. If coolant level had dropped below minimum level, set system to maximum heat and run engine at 3000 RPM for 3-5 minutes to remove air from system. Recheck coolant level.
  2. Start and run engine. Press OFF button, then press A/C button. If A/C clutch engages, go to next step. If A/C clutch does not engage, go to «TEST L: A/C SYSTEM INOPERATIVE OR DOES NOT OPERATE CORRECTLY»(ref-96435-S29467393612001041300000).
  3. With engine at normal operating temperature, press PANEL mode button. Set driver's side temperature control to 60°F (16°C), then set to 90°F (32°C). If both driver's side and passenger's side air temperatures go to full cool then to full hot, go to next step. If driver's side air temperature does not go to full cool then to full hot, go to step 9. If passenger's side only does not go to full cool to full hot, go to step 12. If both sides have full hot only, go to «TEST J: FULL HEAT ONLY IN ALL MODES»(ref-96435-S39911114502001042400000). If both sides have only full cool, go to «TEST H: INSUFFICIENT, ERRATIC OR NO HEAT»(ref-96435-S39633700952001041300000).
  4. Connect New Generation Star (NGS) tester. Enter module identification mode. Read PID CNFG data 1. If PID CNFG data reads ON and 4N_3N_2Y, go to next step. If PID CNFG data does not read ON and 4N_3N_2Y, reconfigure DATC module.
  5. Request continuous DTCs. Perform DATC module self-diagnostic test. See «ENTERING SELF-DIAGNOSTICS»(ref-96435-S03443942982001041300000) under SELF-DIAGNOSTICS. Record any DTCs. If any DTCs exist, see «DATC SELF-DIAGNOSTIC TEST CODE INDEX»(ref-96435-S30839635392001041300000) table under SELF-DIAGNOSTICS. If no DTCs exist, go to next step.
  6. Turn ignition off. Check driver's side, passenger's side, evaporator core, and ambient temperature sensors for proper installation. Check in-car temperature sensor and venturi hose for proper installation. If sensors are installed properly, go to next step. If any sensor(s) are not installed properly, correct sensor installation. Recheck system operation.
  7. Check heater hose connections for proper installation. If heater hoses are installed properly, go to next step. If heater hoses are not installed properly, correct installation as necessary. Recheck system operation.
  8. Press PANEL and A/C buttons. Set passenger's side temperature to 75°F (24°C). Using driver's side temperature control button, set temperature to 65°F (19°C), then to 85°F (29°C). If driver's side temperature decreases and then increases, go to next step. If driver's side air temperature has full cool only, go to step 10. If driver's side air temperature has full hot only, go to step 11.
  9. Press PANEL and A/C buttons. Set driver's side temperature to 75°F (24°C). Using passenger's side temperature control button, set temperature to 65°F (19°C), then to 85°F (29°C). If passenger's side temperature decreases and then increases, system is operating properly at this time. If passenger's side air temperature has full cool only, go to step 10. If passenger's side air temperature has full hot only, go to step 11.
  10. Remove passenger side cowl cover. Start and run engine to normal operating temperature. Set temperature to 90°F (32°C). Check if both heater inlet hoses are too hot to handle. If both heater inlet hoses are too hot to handle, go to step 12. If both heater inlet hoses are not too hot to handle, go to «TEST H: INSUFFICIENT, ERRATIC OR NO HEAT»(ref-96435-S39633700952001041300000).
  11. Remove passenger's side cowl cover. Clamp off 3 heater hoses going to heater core, as close to heater core as possible. Start and run engine. Set temperature to 60°F (16°C). If cooling is restored, problem may be with coolant control valve. Go to «TEST J: FULL HEAT ONLY IN ALL MODES»(ref-96435-S39911114502001042400000). If cooling is not restored, go to next step.
  12. Turn ignition off. Disconnect Passenger's side discharge air temperature sensor 2-pin harness connector C255. Disconnect driver's side discharge air temperature sensor 2-pin harness connector C235. Disconnect DATC module 22-pin harness connector C228a. Measure resistance of White/Black wire between passenger's side air temperature sensor harness connector C255 and DATC module harness connector C228a terminal No. 18. (Scheme 25) Measure resistance of White/Green wire between driver's side air temperature sensor harness connector C235 and DATC module harness connector C228a terminal No. 6. If resistances are less than 5 ohms, recheck all connections. Connect all connectors and recheck system operation. If resistance(s) is 5 ohms or more, ensure White/Black and White/Green wire terminals are making good contact to DATC module. Repair as necessary.

TEST L: A/C SYSTEM INOPERATIVE OR DOES NOT OPERATE CORRECTLY

  1. Ensure ambient temperature is above 32°F (0°C). Start engine and run to operating temperature. Press PANEL and A/C buttons. If full heat exists at all temperature settings, go to «TEST J: FULL HEAT ONLY IN ALL MODES»(ref-96435-S39911114502001042400000) . If full heat does not exist at all temperature settings, go to next step.
  2. Connect New Generation Star (NGS) tester. Turn ignition on. Perform PCM self-diagnostic test. Record DTCs. Perform DATC module self-diagnostic test. If any PCM DTCs exist, see «PCM DTC INDEX»(ref-96435-S40444100432001041300000) table under TROUBLE SHOOTING. Diagnose and repair as directed. If any DATC module DTCs exist, see «DATC SELF-DIAGNOSTIC TEST CODE INDEX»(ref-96435-S30839635392001041300000) table under SELF-DIAGNOSTICS. Diagnose and repair as directed. If no DTCs exist, go to next step.
  3. Ensure ambient temperature is above 50°F (10°C). Turn ignition on. Turn DATC system OFF. Perform PCM Parameter Identification WOT A/C Primary Circuit Fault (PID WACF) test. If PID WACF reads YES perform PCM self-diagnostic test. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If PID WACF does not read YES, go to next step.
  4. Start engine and run at idle. Press PANEL and A/C buttons. Ensure A/C indicator is illuminated. Perform PCM PID WACF test. If PID WACF reads YES, perform PCM self-diagnostic test. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If PID WACF does not read YES, go to next step.
  5. Ensure PID EXTFT2 reading is more than 32°F (0°C). Ensure PID ACPEVAP reading is more than 35°F (2°C). Run engine at idle. Press PANEL and A/C buttons. Ensure A/C indicator is illuminated. Perform PCM Parameter Identification A/C Cycling Switch (PID ACCS) test. If PID ACCS reads ON, go to next step. If PID ACCS does not read ON, replace DATC module. Recheck system operation.
  6. Press PANEL and A/C button. Ensure A/C indicator is illuminated. Perform PCM Parameter Identification WOT A/C Circuit (PID WAC) test. If PID WAC reads ON, go to next step. If PID WAC does not read ON, perform PCM self-diagnostic test. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
  7. Turn ignition off. Connect manifold gauge set to service ports and observe pressure. If pressure is between 50-250 psi (3.5-17.6 kg/cm 2 ), go to next step. If pressure is not between 50-250 psi (3.5-17.6 kg/cm 2 ), check refrigerant system for leaks and service as needed. Recheck system operation.
  8. Remove A/C clutch relay from Underhood Auxiliary Junction Box (UAJB). Turn ignition on. Measure voltage between ground and A/C clutch relay socket terminal No. 3. If more than 10 volts exists, go to step 13 . If 10 volts or less exists, go to next step.
  9. Check fuse F101 (10-amp) in UAJB, located in right front of engine compartment. If fuse is blown, go to next step . If fuse is okay, repair open in Red wire between fuse F101 and splice S136. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation.
  10. Ensure ignition is off. On models with 3.9L engine, remove auxiliary coolant pump relay from UAJB. On all models, remove A/C clutch relay from UAJB. Disconnect coolant control valve jumper harness and engine compartment wiring 6-pin harness connector C134. Measure resistance between ground and A/C clutch relay socket terminal No. 3 (Red wire). If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in Red wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation.
  11. Remove A/C clutch relay from Underhood Auxiliary Junction Box (UAJB). Test A/C clutch relay. See «MICRO ISO RELAY»(ref-96435-S09731459222001042400000) under COMPONENT TESTS. If relay is okay, go to next step. If relay is not okay, replace A/C clutch relay. Recheck system operation.
  12. Install A/C clutch relay. Install fuse F101 in UAJB. Disconnect A/C clutch 2-pin harness connector C100. Press A/C button. If fuse F101 (10-amp) blows, repair short to ground in Green/Yellow wire between A/C clutch and A/C clutch relay. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation.
  13. Remove and test A/C clutch relay. See «MICRO ISO RELAY»(ref-96435-S09731459222001042400000) under COMPONENT TESTS. If relay is okay, go to next step. If relay is not okay, replace A/C clutch relay. Recheck system operation.
  14. Turn ignition off. Install A/C clutch relay. Disconnect A/C clutch 2-pin harness connector C100. Start engine and let idle. Measure voltage between ground and A/C clutch harness connector C100 Green/Yellow wire terminal. If more than 10 volts exists, go to next step. If 10 volts or less exists, repair open in Green/Yellow wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation.
  15. Turn ignition off. Measure voltage between ground and A/C clutch harness connector C100 Green/Yellow wire terminal. If more than 10 volts exists, go to next step. If 10 volts or less exists, repair open in Green/Yellow wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation.
  16. Measure resistance between A/C clutch terminals. If resistance is more than 6 ohms, replace A/C clutch. If resistance is 6 ohms or less, go to next step.
  17. Check A/C clutch air gap. Air gap should be 0.014-0.030" (0.35-0.75 mm). If air gap is not as specified, adjust as necessary. See COMPRESSOR SERVICING article under GENERAL SERVICING. If air gap is as specified, reconnect all connectors. Start engine. Press PANEL and A/C buttons. If fuse F101 blows, replace A/C clutch. Recheck system operation.

TEST M: A/C IS ALWAYS ON

  1. Connect New Generation Star (NGS) tester. Turn ignition on. Perform PCM self-diagnostic test. Record any DTCs. Perform DATC module self-diagnostic test. See «ENTERING SELF-DIAGNOSTICS»(ref-96435-S03443942982001041300000) under SELF-DIAGNOSTICS. If any PCM DTCs exist, see «PCM DTC INDEX»(ref-96435-S40444100432001041300000) table. Diagnose and repair as directed. If any DATC module DTCs exist, see «DATC SELF-DIAGNOSTIC TEST CODE INDEX»(ref-96435-S30839635392001041300000) table under SELF-DIAGNOSTICS. Diagnose and repair as directed. If no DTCs exist, go to next step.
  2. Start engine. Toggle between DATC OFF and A/C buttons. If A/C indicator light illuminates when A/C button is pushed and goes out when OFF button is pushed, go to next step. If A/C indicator light does not illuminate when A/C button is pushed and/or go out when OFF button is pushed, replace DATC module. Recheck system operation.
  3. Monitor PCM Parameter Identification A/C Cycling Switch (PID ACCS). Turn ignition on. Push DATC OFF button, then push A/C button. If A/C indicator light turns off and on and PCM PID ACCS continues to read ON, perform data link diagnostic test. See appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT. If A/C indicator light does not turn off and on and/or PCM PID ACCS does not continue to read ON, go to next step.
  4. Turn ignition on. Push DATC OFF button. Monitor PCM PID WACF. If PCM PID WACF reads YES, repair short to ground in Brown/Blue wire between PCM and A/C clutch relay. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation. If PCM PID WACF does not read YES, go to next step.
  5. Turn ignition off. Disconnect A/C clutch 2-pin harness connector C100. Turn ignition on. Measure voltage between ground and A/C clutch harness connector C100 Green/Yellow wire terminal. If more than 10 volts exists, go to next step. If 10 volts or less exists, check and adjust air gap to 0.014-0.030" (0.35-0.75 mm).
  6. Turn ignition off. Remove A/C clutch relay from Underhood Auxiliary Junction Box (UAJB), located in right front of engine compartment. See «MICRO ISO RELAY»(ref-96435-S09731459222001042400000) under COMPONENT TESTS. If relay is okay, repair short to power in Green/Yellow wire between A/C clutch and A/C clutch relay. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation. If relay is not okay, replace A/C clutch relay. Recheck system operation.

TEST N: INSUFFICIENT A/C COOLING

  1. Turn ignition off. Clamp off heater core inlet and outlet hoses at heater core. Turn ignition on. Set DATC module driver's and passenger's side temperature settings to full cool. Note discharge air temperature. If A/C cooling is restored, go to «TEST K: DUAL TEMPERATURE CONTROL INOPERATIVE OR DOES NOT OPERATE PROPERLY»(ref-96435-S40669411642001042500000) . If A/C cooling is not restored, go to next step.
  2. Ensure evaporator core discharge air temperature sensor is properly installed. If evaporator core discharge air temperature sensor is installed properly, go to next step. If evaporator core discharge air temperature sensor is not installed properly, correct installation. See «DISCHARGE AIR TEMPERATURE SENSOR»(ref-96435-S30926488712001042500000) under REMOVAL & INSTALLATION. Recheck system operation.
  3. Press PANEL and A/C buttons. Set temperature to maximum cooling 60°F (16°C). Press RECIRC button. If cooling performance improves, check cabin air filter for blockage. Recheck system operation. If cooling performance does not improve, go to next step.
  4. Connect manifold gauge set. Start and run engine at 1500 RPM. Set A/C controls to MAX A/C position. Set blower/fan on high speed and close doors and windows. Insert thermometer in center vent. Operate system for 10-15 minutes to allow system to stabilize. When system has stabilized, check and record center register and ambient air temperature. Compare readings with «AMBIENT/CENTER REGISTER TEMPERATURE SPECIFICATIONS»(ref-96435-S34109513462001041300000) table. If readings are within specification, system is functioning normally. If readings are not within specification, go to next step. AMBIENT/CENTER REGISTER TEMPERATURE SPECIFICATIONS Ambient Temp. - °F (°C) Center Register Temp. - °F (°C) 60 (16) 33-47 (0.6-8) 70 (21) 33-47 (0.6-8) 80 (27) 33-47 (0.6-8) 90 (32) 33-47 (0.6-8) 100 (38) 36-48 (2-9)
  5. Check and record ambient temperature and compressor discharge (high) pressure. Compare readings with «AMBIENT TEMPERATURE/DISCHARGE PRESSURE SPECIFICATIONS»(ref-96435-S04810662182001041300000) table. If readings are within specification, system is operating normally at this time. If readings are not within specification, go to next step. AMBIENT TEMPERATURE/DISCHARGE PRESSURE SPECIFICATIONS Ambient Temp. - °F (°C) Discharge Pressure - psi (kg/cm 2 ) 60 (16) 75-175 (5-12) 70 (21) 100-200 (7-14) 80 (27) 125-225 (9-16) 90 (32) 150-250 (11-18) 100 (38) 175-350 (12-25)
  6. Check and record ambient temperature and compressor suction (low) pressure. Compare readings with «AMBIENT TEMPERATURE/SUCTION PRESSURE SPECIFICATIONS»(ref-96435-S14524722252001041300000) table. If readings are within specification, go to next step. If readings are not within specification, go to step 9 . AMBIENT TEMPERATURE/SUCTION PRESSURE SPECIFICATIONS Ambient Temp. - °F (°C) Suction Pressure - psi (kg/cm 2 ) 60 (16) 24-45 (2-3) 70 (21) 24-45 (2-3) 80 (27) 24-45 (2-3) 90 (32) 24-45 (2-3) 100 (38) 38-60 (3-4)
  7. Check and record ambient temperature and total compressor clutch cycle time (time on plus time off) in seconds. Compare readings with «AMBIENT TEMPERATURE/CLUTCH CYCLE TIME SPECIFICATIONS»(ref-96435-S21716316092001041300000) table. If readings are above upper limit of specification, go to next step. If readings are within specification, repair evaporator core for partial restriction or plugged condition. Recheck system operation. AMBIENT TEMPERATURE/CLUTCH CYCLE TIME SPECIFICATIONS Ambient Temp. - °F (°C) Clutch Cycle Time - Seconds 60 (16) 28-50 70 (21) 30-65 80 (27) 45-120 90 (32) 95-Continuous
  8. Check and record ambient temperature and total compressor off time in seconds. Compare readings with «AMBIENT TEMPERATURE/CLUTCH OFF TIME SPECIFICATIONS»(ref-96435-S05729774882001041300000) table. If readings are above upper limit of specification, repair system for excessive moisture or refrigerant oil condition. Recheck system operation. If readings are within specification, go to next step. AMBIENT TEMPERATURE/CLUTCH OFF TIME SPECIFICATIONS Ambient Temp. - °F (°C) Clutch Off Time - Seconds 60 (16) 17-24 70 (21) 14-23 80 (27) 2-17 90 (32) 2-3
  9. If readings in step 3 are above upper limit of specification, repair evaporator core orifice for missing or damaged "O" rings. Recheck system operation. If readings in step 3 are not above upper limit of specification, replace A/C cycling switch for low cut-out condition. Recheck system operation.
  10. Refer to readings obtained in step 8 . If ambient temperature is above 80°F (27°C), this is normal operation for refrigerant system in high humidity conditions. If ambient temperature is not above 80°F (27°C), repair system for overcharge condition. Recheck system operation.
  11. Refer to readings obtained in step 5 . If reading is above upper limit of specification, go to next step. If reading is not above upper limit of specification, go to step 14 .
  12. Check and record ambient temperature and compressor suction (low) pressure. Compare readings with «AMBIENT TEMPERATURE/SUCTION PRESSURE SPECIFICATIONS»(ref-96435-S14524722252001041300000) table. If readings are within specification, repair engine for overheating condition. Recheck system operation. If readings are not within specification, go to next step.
  13. Refer to readings obtained in step 6 . If reading is below lower limit of specification, repair or replace thermostatic expansion valve for partially restricted or plugged condition. Recheck system operation. If reading is not below lower limit of specification, repair condenser core for partially blocked or inadequate airflow condition. Recheck system operation.
  14. Check and record ambient temperature and compressor suction (low) pressure. Compare readings with «AMBIENT TEMPERATURE/SUCTION PRESSURE SPECIFICATIONS»(ref-96435-S14524722252001041300000) table. If readings are within specification, go to next step. If readings are not within specification, go to next step.
  15. Check and record ambient temperature and total compressor clutch cycle time (time on plus time off) in seconds. Compare readings with «AMBIENT TEMPERATURE/CLUTCH CYCLE TIME SPECIFICATIONS»(ref-96435-S21716316092001041300000) table. If readings are above upper limit of specification, replace thermostatic expansion valve manifold and tube assembly for partially restricted or plugged condition. Recheck system operation. If readings are within specification, go to next step.
  16. Check and record ambient temperature and total compressor off time in seconds. Compare readings with «AMBIENT TEMPERATURE/CLUTCH OFF TIME SPECIFICATIONS»(ref-96435-S05729774882001041300000) table. If reading is within specification, repair evaporator core for low or restricted airflow. Recheck system operation. If readings are not within specification, go to next step.
  17. Refer to readings obtained in step 13 . If reading is above upper limit of specification, repair or replace condenser core for partially or plugged condition. Recheck system operation. If reading is not above upper limit of specification, repair system for low refrigerant condition.

Scheme 30

Scheme 30: TEST O: BLOWER MOTOR INOPERATIVE OR DOES NOT OPERATE PROPERLY
Scheme 30: TEST O: BLOWER MOTOR INOPERATIVE OR DOES NOT OPERATE PROPERLY

Scheme 31

Scheme 31
Scheme 31
  1. Turn ignition on. Press PANEL on DATC panel. Operate fan in all speeds. If fan operates at high speed with only 7 bars showing on DATC display, go to «TEST Q: NO OPERATION IN SOME BLOWER SPEEDS»(ref-96435-S18503860412001042600000). If fan does not operate at high speed with only 7 bars showing on DATC display panel, go to next step.
  2. Ensure Green 16-pin harness connector C260, located on evaporator housing, is connected. If harness connector C260 is connected, go to next step. If harness connector C260 is not connected, reconnect connector C260 and recheck system operation.
  3. Turn ignition off. Remove fuse F116 (30-amp) from Underhood Auxiliary Junction Box (UAJB), located in right front of engine compartment. If fuse is okay, go to next step. If fuse F116 is blown, replace fuse F116. Recheck system operation. If fuse F116 blows again, go to next step.
  4. Turn ignition off. Remove blower motor relay from UAJB. Turn ignition on. If fuse F116 blows, repair Red/Orange wire between fuse F116 and blower motor relay. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation. If fuse F116 does not blow, go to next step.
  5. Remove blower motor relay from UAJB. Measure voltage between ground and blower motor relay socket terminal No. 86 (Red/Orange wire). If more than 10 volts exists, go to next step. (Scheme 31) If 10 volts or less exists, repair open in Red/Orange wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  6. Measure resistance between ground and blower motor relay socket terminal No. 85 (Black/Blue wire). If resistance is less than 10 ohms, go to next step. If resistance is 10 ohms or more, repair open or high resistance in Black/Blue wire between blower motor relay and DATC. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  7. Test blower motor relay. See «MINI ISO RELAY»(ref-96435-S41979537752001042600000) under COMPONENT TESTS. If blower motor relay is okay, go to next step. If blower motor is not okay, replace blower motor relay. Recheck system operation.
  8. Disconnect blower motor speed control 5-pin harness connector C297. Connect fused jumper wire between blower motor speed control harness connector C297 terminals No. 4 (Black/Red wire) and No. 5 (Black wire). Turn ignition on. If blower motor operates, reconnect blower motor speed control connector and recheck system operation. If blower motor still does not operate, go to step 13. If blower motor does not operate, go to next step.
  9. Turn ignition off. Disconnect blower motor 2-pin harness connector C288. Connect blower motor speed control connector. Turn ignition on. Set blower motor speed to high. Measure voltage between blower motor harness connector C288 Red/Black and Black/Red wire terminals. If more than 10 volts exists, replace blower motor. Recheck system operation. If 10 volts or less exists, go to next step.
  10. Turn ignition off. Remove blower motor relay from UAJB. Measure resistance between ground and blower motor harness connector C288 Red/Black wire terminal. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in Red/Black wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  11. Remove fuse No. 116 (30-amp) from UAJB. Turn ignition off. Remove blower motor relay from UAJB. Disconnect blower motor 2-pin harness connector C288. Measure resistance of Red/Black wire between blower motor relay socket terminal No. 87 and blower motor harness connector C288. If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open or high resistance in Red/Black wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  12. Connect blower motor connector. Disconnect blower motor speed control 5-pin harness connector C297. Turn ignition on. Measure voltage between ground and blower motor speed control harness connector C297 terminal No. 4 (Black/Red wire). If more than 10 volts exists, go to next step. If 10 volts or less exists, repair open in Black/Red wire between blower motor and blower motor speed control. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.
  13. Turn ignition off. Measure resistance between ground and blower motor speed control harness connector C297 terminal No. 5 (Black wire). (Scheme 25) If resistance is more than 5 ohms, repair open or high resistance in Black wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation. If resistance is 5 ohms or less, go to next step.
  14. Connect blower motor speed control connector. Turn ignition on. Set blower motor speed to less than high (1-6 bars). Using DVOM connected to ground, measure voltage by backprobing DATC module harness connector C228a terminal No. 15 (Brown/Blue wire). (Scheme 25) Note voltage. Set blower motor speed to high (7 bars). Using DVOM connected to ground, measure voltage by backprobing DATC module harness connector C228b terminal No. 8 (Gray/Violet wire). (Scheme 26) If 1-3 volts exists at DATC module harness connector C228a terminal No. 15 and more than 10 volts exist at DATC module harness connector C228b terminal No. 8, replace blower motor speed control. Recheck system operation. If 1-3 volts does not exist at DATC module harness connector C228a terminal No. 15, go to next step. If more than 10 volts does not exist at DATC module harness connector C228b terminal No. 8, go to step 16. If 1-3 volts does not exist at connector C228a terminal No. 15 and more than 10 volts does not exist at connector C228b terminal No. 8, go to next step.
  15. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Disconnect blower motor speed control 5-pin harness connector C297. Measure resistance of Brown/Blue wire between blower motor speed control harness connector C297 terminal No. 2 and DATC module harness connector C228a terminal No. 15. If resistance is 5 ohms or more, repair open or high resistance in Brown/Blue wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). If resistance is less than 5 ohms, recheck all terminals. Reconnect all connectors and recheck system operation. If system still does not operate properly and less than one volt existed at DATC module harness connector C228a terminal No. 15 in step 14, replace DATC module. Recheck system operation.
  16. Turn ignition off. Disconnect DATC module 26-pin harness connector C228b. Measure resistance of Gray/Violet wire between blower motor speed control harness connector C297 terminal No. 3 and DATC module harness connector C228a terminal No. 15. (Scheme 25)and see scheme 10. If resistance is less than 5 ohms, recheck all terminals and reconnect all connectors. Recheck system operation. If system operation is still not correct, replace DATC module. If resistance is 5 ohms or more, repair open or high resistance in Gray/Violet wire. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000). Recheck system operation.

TEST P: BLOWER MOTOR OPERATES CONTINUOUSLY IN HIGH SPEED

  1. Turn ignition on. Press PANEL button. Adjust blower speed to high speed and then to low speed. If blower motor speed changes from high to low speed, system is operating normally at this time. If blower speed does not change from high to low speed, go to next step.
  2. Turn ignition off. Disconnect blower motor speed control 5-pin harness connector C297. Turn ignition on. If blower motor is running, repair short to power in Black/Red wire between blower motor and blower motor speed control. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation. If blower motor is not running, go to next step.
  3. Turn ignition off. Connect blower motor speed control connector. Disconnect 16-pin in-line connector C260. Turn ignition on. If blower motor is running, replace blower motor speed control. Recheck system operation. If blower motor is not running, go to next step.
  4. Turn ignition off. Disconnect blower motor speed control 5-pin harness connector C297. Connect in-line connector C260. Disconnect DATC module 22-pin harness connector C228a. Disconnect DATC module 26-pin harness connector C228b. Turn ignition on. Measure voltage between ground blower motor speed control harness connector C297 terminal No. 2 (Brown/Blue wire). Measure voltage between ground blower motor speed control harness connector C297 terminal No. 3 (Gray/Violet wire). If more than 10 volts exists at either terminals, repair short to power in appropriate wire. If 10 volts or less exists, replace DATC module. Recheck system operation.

TEST Q: TEMPERATURE SET POINT DOES NOT REPEAT AFTER TURNING IGNITION SWITCH OFF

Note. Some vehicles are shipped with a transit relay. Ensure transit relay, packaged in trunk, is not installed.

  1. Turn ignition on. Set driver's side temperature to 72°F (22.2°C). Turn ignition off. Set passenger's side temperature to 74°F (23.3°C). Wait 5 seconds. Turn ignition on. If set points repeat, system is operating properly at this time. If set points do not repeat, go to next step.
  2. Turn ignition off. Disconnect DATC module 22-pin harness connector C228a. Measure voltage between ground and DATC module harness connector C228a terminal No. 14 (Orange/Green wire). If more than 10 volts exists, replace DATC module. Recheck system operation. If 10 volts or less exists, go to next step.
  3. Remove fuse F214 (10-amp) from Central Junction Box (CJB). Measure resistance of Orange/Black wire between CJB fuse F214 socket terminal and DATC module harness connector C228a terminal No. 14. If resistance is less than 5 ohms, repair Pink/White wire between CJB and ignition switch. See «WIRING DIAGRAMS»(ref-96435-S06818458582001041300000) . Recheck system operation.

TEST R: EXTERIOR TEMPERATURE DISPLAY DOES NOT FUNCTION PROPERLY

  1. Turn ignition on. Perform DATC module self-diagnostic test and retrieve continuous DTCs. See «ENTERING SELF-DIAGNOSTICS»(ref-96435-S03443942982001041300000) under SELF-DIAGNOSTICS. If any DTCs exist, see «DATC SELF-DIAGNOSTIC TEST CODE INDEX»(ref-96435-S30839635392001041300000) under SELF-DIAGNOSTICS. If no DTCs exist, go to next step.
  2. Turn ignition on. Press AUTO button. Press EXT button several times. If display alternates between interior set temperatures and exterior temperature, go to next step. If display does not alternate between interior set temperatures and exterior temperature, replace DATC module. Recheck system operation.
  3. Check mounting of ambient temperature sensor. Check ambient temperature and verify DATC exterior temperature displayed. If temperature displayed matches ambient temperature, system is operating properly at this time. If temperature displayed does not match ambient temperature, replace ambient temperature sensor.

SELF-DIAGNOSTICS

The DATC module self-diagnostic test will detect problems in system control functions. It will display hard DTCs and intermittent DTCs during system operation. If a DTC is continuous and does not appear in self-diagnostic test, this indicates an intermittent fault condition, such as a poor wiring connection or loose terminal. If DTC does not appear after running self-diagnostic test, this may also indicate DTC no longer exists. If DTC is continuous and appears in self-diagnostic test, this indicates a hard fault. Check for a permanent wire failure, disconnected connector or component failure.

If DATC module cannot be accessed by New Generation Star (NGS) tester, go to TEST A: NO COMMUNICATION WITH DATC MODULE . If DATC module self-diagnostic test will not detect concerns associated with DLC messages, an NGS tester will have to be used to retrieve these messages.

ENTERING SELF-DIAGNOSTICS

  1. Ensure in-car temperature is between 32-90°F (0-32°C). Simultaneously depress OFF and FLOOR buttons, then press AUTO button within 2 seconds. see scheme 1 Display will show counts of 1-25 in center of display window. DTCs will be displayed as 4-digit DTCs without the alpha character. Record all DTCs as displayed. If no DTCs exist, display will illuminate all elements.
  2. If DTCs are displayed, perform test indicated. See «DATC SELF-DIAGNOSTIC TEST CODE INDEX»(ref-96435-S30839635392001041300000) table. If a condition exists but no DTCs are displayed, diagnose problem by symptom. See «SYMPTOM INDEX»(ref-96435-S31810387532001041600000) table under SYMPTOM TESTS.
  3. Self-diagnostics can be initiated at any time with the resulting DTCs being displayed. Normal system operation is stopped when system is in self-diagnostic mode.
DTCDATC Self-Test & (Intermittent) Fault (Run Time Code)DescriptionPerform Test
B12421242Recirculation Door Actuator ShortC
B12511251In-Vehicle Temp. Sensor Circuit OpenD
B12531253In-Car Temp. Sensor Circuit Short To GroundD
B12551255Ambient Air Temp. Sensor OpenF
B12571257Ambient Air Temp. Sensor Short To GroundF
B12591259Sunload Sensor Open CircuitG
B12611261Sunload Sensor Circuit Short To GroundG
B12621262Defrost Door Actuator Circuit FailureC
B12631263Panel Door Actuator Circuit FailureC
B12641264Floor Door Actuator Circuit FailureC
B12651265Cold Air By-Pass Door Actuator Circuit FailureC
B13421342ECU Defective(1)
B16761676Battery Voltage Out Of Range(2)
B19461946Evaporator Discharge Temp. Sensor Circuit OpenE
B19471947Evaporator Discharge Temp. Sensor Circuit Short To GroundE
B19661966Driver Heater Core Discharge Temp. Sensor Circuit OpenE
B19671967Driver Heater Core Discharge Temp. Sensor Short CircuitE
B24282428Passenger Heater Core Discharge Temp. Sensor Open CircuitE
B24292429Passenger Heater Core Discharge Temp. Sensor Short CircuitE
B24772477Module Configuration Failure(3)
U10415041SCP Invalid Or Missing Data For Function Read Vehicle Speed(4)
U10735073SCP Invalid Or Missing Data For Engine Coolant(4)
U11785178SCP Invalid Or Missing Data For Voice Command(5)
U12225222SCP Invalid Or Missing Data For Interior Lamps(6)
(1) Replace DATC Module. (2) See appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS. (3) See appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT. (4) See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. (5) If equipped with voice command. (6) See appropriate ILLUMINATION/INTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT.
(1)Replace DATC Module.
(2)See appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS.
(3)See appropriate MODULE COMMUNICATIONS NETWORK article in ACCESSORIES & EQUIPMENT.
(4)See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
(5)If equipped with voice command.
(6)See appropriate ILLUMINATION/INTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT.

DATC SELF-DIAGNOSTIC TEST CODE INDEX

EXITING SELF-DIAGNOSTICS

Note. Always exit self-diagnostic test before powering system down.

  1. To exit self-diagnostics while retaining DTCs in memory, depress any button other than front defrost. see scheme 1 The DATC module will retain all DTCs, exit self-diagnostics and turn system off (display blank).
  2. To exit self-diagnostics and erase DTCs from memory, press front defrost button. Display will show "888" for 1 second, then will go blank and all DTCs will be cleared. Any intermittent DTCs will be deleted after 80 ignition on-off cycles after condition occurs.

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